Adjust oven rack to middle position and preheat the oven to 375°F. Unroll pie crust into 9-inch pie plate, tucking back edges of crust or crimping as desired.

In a large bowl, whisk together eggs, egg yolks, and sugar until pale and frothy, about 2 minutes. Whisk in flour to combine. Whisk in half and half, and scrape in vanilla seeds, mixing to combine.

Pour egg and half and half mixture into pie crust. Place pie plate on rimmed baking sheet, and bake until egg mixture is puffed and golden, about 55 minutes to 1 hour. Remove from oven and allow to rest for 15 minutes. Serve warm or room temperature, in slices.